The present invention relates generally to tape cartridges in which tape is driven back and forth between two rotatable hubs, and is particularly concerned with belt driven, magnetic data tape cartridges of the type used in association with computers and the like.
Magnetic data tape cartridges are available in two basic sizes, the 51/4" standard cartridge and the 31/2" mini cartridge, for fitting in conventional drive units. A typical mini magnetic data tape cartridge is a rectangular housing in which a pair of rotatable tape spools or hubs are mounted. The spools are aligned on an axis parallel to the front wall of the housing in which the tape drive and tape read/write openings are located. The tape is driven between the spools by means of a flexible elastic drive belt which extends around a drive roller at the front of the housing and contacts the tape on the two spools before extending around a pair of corner rollers. The drive belt is moved by rotating the drive roller in order to move the tape between the spools. The cartridge is inserted in a tape drive in order to read data from the tape or write data onto the tape.
Typical tape drive software, until recently, has required a fixed tape length, such as 300 feet for the mini size cartridge. Additionally, the amount of tape which can be accommodated in the relatively small, conventional mini cartridge is limited by the maximum separation permitted between the two spools. However, tape drive software now permits variable tape lengths, and by increasing the length of tape in the housing, the amount of data which may be stored is increased. There is a need for tape cartridges capable of holding a greater length of tape. Some enlarged tape cartridges for holding double the normal length of tape have been proposed, but these require modification of the drive to receive the-larger-cartridge.